There were also about 350 sugar gliders -- a type of small marsupial -- cockatoos, parrots and parakeets found in boxes on board, he said, adding the smugglers intended to sell all the animals as pets.

The smugglers were seeking to transport the animals under cover of darkness in a cargo vessel from the vast, jungle-clad Indonesian island of Sumatra, through the Malacca Strait to Thailand, customs chief T. Subromaniam told the Star newspaper.

Orangutan (file).

But Malaysian customs officers received information about the boat and intercepted it, Subromaniam said.

The arrested Indonesians, who were on the vessel when it was stopped, are expected to be charged in court for breaking wildlife laws and could face up to 10 years in jail, Mohamad Zaki said.

Elizabeth John, spokeswoman for wildlife trade watchdog Traffic, said that the number and variety of animals seized showed "how tremendous the pressure is on wildlife due to demand for pets".

Authorities in Malaysia, a tropical Southeast Asian country that is home to many rare species, regularly thwart smuggling attempts, but finding 400 animals at the same time is unusual.

In June 2017, Thai authorities nabbed a Malaysian trying to smuggle two juvenile orangutans and some 60 other animals in a taxi through the country's southern border.